In an electronic device including an image-capturing function, such as a digital still camera and a digital video camera, a camera shake correction system that corrects a camera shake in capturing to output an image free from the camera shake has been adopted in the past. There are two types of existing camera shake corrections: an electronic camera shake correction and an optical camera shake correction.
In the electronic camera shake correction, the camera shake is corrected by detecting a shake of a subject being captured from a captured image between continuous images, and performs image processing of moving a position of the image according to the shake amount. Such an electronic camera shake correction eliminates the need for a mechanical mechanism, and allows a structure to be downsized. However, since the shake is detected from the image, it has been difficult to detect the shake when the image is not clear in a dark place. Further, the comparison with the previous images requires a memory area for storing all of the previous images.
Moreover, in the electronic camera shake correction, since the camera shake amount is detected from two frames (images), it is extremely difficult to securely determine a moving object (dynamic body) in the image or a shift of the image due to the camera shake in every scene. Many algorithms including the determination of the dynamic body or the camera shake have been proposed, but have been being still improved at this time.
Moreover, in the optical camera shake correction, the camera shake is corrected by detecting how an image sensor has shaken by using a gyro or the like, and allowing a lens or the image sensor to operate by an increment of the reverse correction. In the optical camera shake correction, since the physical shake is detected, false recognition between the dynamic body and the camera shake does not occur unlike the electronic camera shake correction. Further, since the comparison with the previous images is not necessary, the frame memory for accumulating the previous pictures is not necessary. However, the optical camera shake correction not only increases a size of a structure of the operation unit, but increases power consumption due to the operation of the structure.
Further, in an image-capturing device adopting a complementary metal oxide semiconductor (CMOS) image sensor as an image-capturing element, since a shift of an exposure period (a shift of image-capturing timing) occurs for each line of the image-capturing element, it has been difficult to fully remove the effect of the camera shake in the past.
Accordingly, there has been proposed the camera shake correction processing of correcting the subject image for each line on the basis of the correction amount calculated from the shake amount when a predetermined line in the subject image is captured (see, for example, Patent Literature 1).